A packaged semiconductor device has a plurality of leads or electrodes projected from a package body. This sort of semiconductor device is subjected to an electrical test by using an electrical connecting apparatus called socket. There are such electrical connecting apparatus as described in Patent Documents 1 and 2.
Patent Document 1: Japanese Patent Appln. Public Disclosure No. 11-31566
Patent Document 2: Japanese Patent Appln. Public Disclosure No. 2003-297506
The electric connecting apparatus described in Patent Documents 1 and 2 comprise: a plurality of probes having a curved portion; a housing with the probes arranged in parallel; and rod-like needle retainers or elastic members disposed in the housing so as to extend in the arrangement direction of the probes.
The housing is mounted on a base plate such as a wiring board with a plurality of screw members. The probes are pressed at the outside surface of the curved portion against an conductive portion of the base plate by the needle retainers.
A device under test, when its electrodes are pressed by the front ends (tips) of the probes, is electrically connected to the electrodes of the base plate by the probes.
In the foregoing electrical connecting apparatus, however, since the outside surface of the curved portion of the probe is only brought into contact with the conductive portion of the base plate in a state that the housing is attached to the base plate, the probes tend to drop off in a state before the housing is attached to the base plate; therefore, assembling is troublesome.
In the electrical connecting apparatus described in Patent Document 2, if the elastic member is close-fitted into the probe, attitudes of adjoining probes in a state of being attached to the elastic member do not coincide, and an accurate electrical test cannot be conducted.